Problem: If one-fourth of $2^{30}$ is equal to $2^x$, what is $x$?
Answer: We have  \[\frac14\cdot 2^{30} = \frac{2^{30}}{4} = \frac{2^{30}}{2^2} = 2^{30-2} = 2^{28},\] so $x = \boxed{28}$.